10
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: not found

      Blood pressure regulation and cardiac autonomic control in mice overexpressing alpha- and gamma-melanocyte stimulating hormone.

      1 , , ,

      Peptides

      Elsevier BV

      Read this article at

      ScienceOpenPublisherPubMed
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Melanocyte stimulating hormones (MSH) derived from pro-opiomelanocortin have been demonstrated to participate in the central regulation of cardiovascular functions. The aim of the present study was to elucidate the chronic effects of increased melanocortin activation on blood pressure regulation and autonomic nervous system function. We adapted telemetry to transgenic mice overexpressing alpha- and gamma-MSH and measured blood pressure, heart rate and locomotor activity, and analyzed heart rate variability (HRV) in the frequency-domain as well as baroreflex function by the sequence technique. Transgenic (MSH-OE) mice had increased systolic blood pressure but their heart rate was similar to wild-type (WT) controls. The 24-h mean of systolic blood pressure was 132+/-7mmHg in MSH-OE and 113+/-4mmHg in WT mice. Locomotor activity was decreased in the MSH-OE mice. Furthermore, MSH-OE mice showed slower adaptation to mild environmental stress in terms of blood pressure changes. The low frequency (LF) power of HRV tended to be higher in MSH-OE mice compared to WT mice, without a difference in overall variability. The assessment of baroreflex function indicated enhanced baroreflex effectiveness and more frequent baroreflex operations in MSH-OE mice. Baseline heart rate, increased LF power of HRV and increased baroreflex activity may all reflect maintenance of baroreflex integrity and an increase in cardiac vagal activity to counteract the increased blood pressure. These results provide new evidence that long-term activation of the melanocortin system elevates blood pressure without increasing heart rate.

          Related collections

          Author and article information

          Journal
          Peptides
          Peptides
          Elsevier BV
          0196-9781
          0196-9781
          Nov 2008
          : 29
          : 11
          Affiliations
          [1 ] Institute of Biomedicine, Department of Pharmacology, Drug Development and Therapeutics, University of Turku, Turku, Finland.
          Article
          S0196-9781(08)00273-8
          10.1016/j.peptides.2008.06.012
          18638516

          Comments

          Comment on this article